The present invention relates to a picture-phone device, and more particularly to a picture-phone device capable of providing an intimate telephone communication between callers on a transmitting and a receiving ends.
A picture-phone device is a device for allowing two persons staying apart to make a conversation looking at images of each other. Therefore, it is preferable for the persons on both ends of the phone to watch a camera of the picture-phone device to each other. In the event the caller's line of sight turns off the position of the camera by a large amount, an image of the caller on one end looking away is seen by the caller on the other end, which may cause a trouble in making a communication smoothly. For example, there is a picture-phone device which provides a function for leading a caller's line of sight to the camera described in unexamined Japanese Patent Publication No. Hei 6-217298 (hereafter called a conventional picture-phone device).
In a conventional picture-phone device, a camera for imaging a caller on a transmitting end is provided behind a screen of a liquid crystal display for projecting a caller on a receiving end. The camera is disposed, for example, at a central portion of the liquid crystal display. And the image of the caller on the transmitting end is transmitted with respect to the picture-phone device of the caller on the receiving end via the camera by providing a specific area on the liquid crystal display with transparency temporally. The above-mentioned specific area can be an area which the camera requires for imaging.
When the picture-phone device transfers the images of thirty frames per second, the specific area on the liquid crystal display is provided with transparency for a certain period of time for transferring image of two frames per second. Then, a usual image is projected during the remaining time for twenty-eight frames (28/30), which gives less uncomfortable feeling to the callers. And two frames of static image are transmitted in one second with respect to the picture-phone device of the caller on the receiving end.
As a caller performs a calling operation watching at a liquid crystal display, the line of sight of the caller on the transmitting end is directed around the center of the liquid crystal display. Therefore, communication between the callers of the transmitting and receiving ends progresses intimately by establishing eye-to-eye contact.
However, the above-mentioned art can not solve the problem that the motion of the image projected on the liquid crystal display during the conversation on the phone gets less active. Because only a few frames (two frames, in the above description) of a static image are transmitted in one second.
Besides, in the event of adding some motions to the image projected on the liquid crystal display during the conversation on the phone, it is necessary to extend the time for providing the specific area on the liquid crystal display with transparency in one second. In the above-mentioned event, the caller is too conscious of the specific area being transparent, which may cause a problem that the image projected on the liquid crystal display gives an uncomfortable feeling.
Further, there are problems that the composition of the conventional picture-phone device becomes complicated and costs for implementation gets high accordingly.